Uber formally launched its ride-summoning smartphone app in Beijing this week. But the Chinese capital has presented the U.S. car service company with a vexing problem: how to handle the city’s bumper-to-bumper traffic.

Saying “Beijing has a traffic problem” is something of an understatement. A 2011 study by UBS showed it to be the worst among a number of Chinese cities it tracked, with average traveling speed time a glacial 12 kilometers per hour. By contrast, traffic in New York goes roughly twice as fast, a fact that would probably shock commuters idling on the Brooklyn-Queens Expressway. To demonstrate the problem, one media outfit once pit a Porsche against a bicycle in a race across the city’s center. (Residents of the city can guess which won.)

Beijing is the last of what are generally considered China’s four tier-one cities that Uber Technologies has entered. The app – which in China connects users with drivers via agreements with rental-car fleet operators and driving services — formally launched in Shanghai in February and has since been launched in the twin southern boomtowns of Guangzhou and Shenzhen.

Such cities also have their traffic problems – and also fared poorly in UBS’s traffic study – but Uber acknowledges Beijing poses a particular problem. In addition to traffic, there’s the city’s sheer geographic size.

“Beijing is a big, complicated city,” said Allen Penn, Uber’s head of Asia. He added, “in short, we can’t change the traffic.”

Its solution is to start…well, slow. The company, which is in 41 countries, soft-launched its Beijing service about three months ago with a focus just on the tony Sanlitun shopping district. With its official launch, it has added the city’s Central Business District. Other rollouts will be gradual, Mr. Penn said. By contrast, when it launched in Shanghai, the app’s reach covered broader swaths of that city.

Penn says Uber is making progress handling the traffic and is using customer data to figure out where to best position cars and drivers. Cars now take an average of about nine minutes to reach Beijing customers, he said, compared with 14 minutes, the average when the company first soft-launched in the city. That figure puts Beijing just behind Shanghai, where customers usually wait about eight minutes for a ride.

Still, the nine-minute wait puts Beijing well behind New York, where rides are filled in three or four minutes, and Singapore, where it takes seven minutes. Ultimately, Penn said, Uber wants to whittle Beijing’s time down to five minutes.

“It’s launch day. It’s day one,” he said, adding, “we have a long way to go, clearly.”